Process of manufacturing balance-wheels for watches.



No. 639,821. f Y Patented ne'e. 2s, |899.

A. MATHEY-nons. PROCESS 0F MANUFACTURING BALANCE WHEELS FUR WATCHES.

(Application lsd Hm, 27. 1899.1 (No Model.)

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.UNITED STATES PATENT CEEICE.

ALFRED MATHEY-DORET, OF LA CHAUX-DE-FONDS, SVITZERLAND.

PROCESS 0F MANUFACTURING BALANCE-WHEELS FOR WATCHES.

SPECIFICATION forming part of Letters Patent N0. 639,821, dated December26, 1899.

Application tiled March 27, 1899. Serial No. 710,650. (N o model.)

To ctZZ whom it may concern.:

Be it known that LALFRED MATHEYQD oRET, a citizen of Switzerland, and aresident of La Chauxde-l1`onds,y ca-nton of Neufchtel, Switzerland,havemade certain new and useful Improvements in Processes for theManufacture of Balance-Wheels for Watches, of which the following is aspecification.

Until now bimetallic balance-wheels-that is to say, those formed by arim composed of two metals, steel and brass-have been made in solderingthe outside brass rim upon the inside steel part.

The process which is the object ot' my in- Vention is totally dierentfrom that one. It consists in plating together two or several metals ormetallic alloys,then in stamping and cutting them out suitably, so as toobtain a bimetallic balance-wheel such as those generally used.

Figure l shows in plan and in section a disk or plate formed of twometals plated together. Fig. 2 shows a plan and section of the diskafter it is subjected to the action of the dies. Fig. 3 shows in planand section the article after it is cut.

The annexed drawings show, as an exam-- ple, the dierent phases throughwhich the manufacture of a balance-wheel must principallygo according toprocess. As it is seen, Fig. l shows in plan and in section a washer ordisk plated of two metals, of which A is, for example, steel, while B isbronze. That disk has been cut into a band or leaf of plated metals, outof which, of course, a certain number of them may be out. In a die of asuitable form the disk is embossed, as is shown in plan and in sectionby Fig. 2, so that the steel A is inside the calotte thus obtained. Thenthe part of B underneath the line mis cut by turning vor milling. Thereis then some of the metal or alloy B left only on the circumference ofthe calotte, and it remains only to cut out the two inside parts a and ato form the arms o and b. It is evident that a balance-wheel thus madewill present more homogeneity and regularity than with the old process.Besides, this new one produces balance-wheels of which the rim may becom posed not only ot' twobut of several metals--` as, for example,copper, steel, and nickel. In this case it would be sufficient to platethose metals together in suitable order and then to proceed for thestamping and cutting out, as described above.

In certain cases the metal B that is at the lower part of the arms b b'below the line @c may be left uncut. The balance-wheel may be thentinishedlike the others. It may be cut to obtain compensation andprovided with any number of screws on the periphery of its rim.

By the term plated is meant two or several metals attached together in asuitable way, either by soldering or by hot pressure with a hydraulicpress or otherwise.

Having now particularly described the nature of my said invention and inwhat manner it may be executed, I declare that what I claim is Theherein-'described process consisting in cutting out from a plate formedof two layers of metal a disk, striking said disk up into cup form,removing the lower layer of the bottom of the cup and cutting out theupper or interiorlay'er to form the arms of the balancewheel.

In witness whereof I have hereunto set my hand in presence of twowitnesses.

ALFRED MATHEY-DOE'ET, Witnesses:

ARMAND TERRELD, JULES CHAPREY.

